/**
 * Copyright (C) 2002-2015   The FreeCol Team
 * <p>
 * This file is part of FreeCol.
 * <p>
 * FreeCol is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 * <p>
 * FreeCol is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * <p>
 * You should have received a copy of the GNU General Public License
 * along with FreeCol.  If not, see <http://www.gnu.org/licenses/>.
 */


package net.sf.freecol.common.networking;

import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;

import net.sf.freecol.common.FreeColException;

import org.w3c.dom.Element;


/**
 * The client connection to a server.
 */
public final class Client
{

    private static final Logger logger = Logger.getLogger( Client.class.getName( ) );

    /**
     * The <code>Connection</code> this <code>Client</code> uses when
     * communicating with the server.
     */
    private final Connection c;

    /** The host to connect to. */
    private final String host;

    /** The port to connect to. */
    private final int port;


    /**
     * Creates a new <code>Client</code>.
     *
     * @param host The host to connect to.
     * @param port The port to connect to.
     * @param handler The <code>MessageHandler<code> to use.
     * @param name The name for the connection.
     * @exception IOException If an exception is thrown while creating
     *     a new {@link Connection}.
     */
    public Client( String host, int port, MessageHandler handler, String name )
            throws IOException
    {
        this.host = host;
        this.port = port;
        c = new Connection( host, port, handler, name );
    }


    /**
     * Gets the host used by the connection.
     *
     * Used in reconnect.
     *
     * @return The host.
     */
    public String getHost( )
    {
        return host;
    }

    /**
     * Gets the port used by the connection.
     *
     * Used in reconnect.
     *
     * @return The port.
     */
    public int getPort( )
    {
        return port;
    }

    /**
     * Gets the <code>Connection</code> this <code>Client</code> uses
     * when communicating with the server.
     *
     * @return The <code>Connection</code>.
     */
    public Connection getConnection( )
    {
        return c;
    }

    /**
     * Sets the <code>MessageHandler</code> for this <code>Client</code>.
     * The <code>MessageHandler</code> is the class responsible for receiving
     * and handling the network messages.
     *
     * @param mh The new <code>MessageHandler</code> for this client.
     */
    public void setMessageHandler( MessageHandler mh )
    {
        c.setMessageHandler( mh );
    }

    /**
     * Disconnects this client from the server.
     */
    public void disconnect( )
    {
        c.close( );
    }


    /**
     * Sends the specified message to the server.
     *
     * @param message The <code>DOMMessage</code> to send.
     * @see #sendAndWait(Element)
     * @see #ask(Element)
     * @exception IOException
     */
    public void send( DOMMessage message ) throws IOException
    {
        c.send( message.toXMLElement( ) );
    }

    /**
     * Sends the specified message to the server.
     *
     * @param element The element (root element in a DOM-parsed XML tree) that
     *                holds all the information
     * @see #sendAndWait(Element)
     * @see #ask(Element)
     * @exception IOException
     */
    public void send( Element element ) throws IOException
    {
        c.send( element );
    }

    /**
     * Sends the specified message to the server and waits for the reply
     * to be returned before returning from this method.
     *
     * @param message The <code>DOMMessage</code> to send.
     * @see #send(Element)
     * @see #ask(Element)
     * @exception IOException
     */
    public void sendAndWait( DOMMessage message ) throws IOException
    {
        c.sendAndWait( message.toXMLElement( ) );
    }

    /**
     * Sends the specified message to the server and waits for the reply
     * to be returned before returning from this method.
     *
     * @param element The element (root element in a DOM-parsed XML tree) that
     *                holds all the information
     * @see #send(Element)
     * @see #ask(Element)
     * @exception IOException
     */
    public void sendAndWait( Element element ) throws IOException
    {
        c.sendAndWait( element );
    }

    /**
     * Sends the specified message to the server and returns the reply.
     *
     * @param message The <code>DOMMessage</code> to send.
     * @return The answer from the server or <code>null</code> if either
     *       an error occured or the server did not send a reply.
     * @see #sendAndWait
     * @see #send
     * @exception IOException
     */
    public Element ask( DOMMessage message ) throws IOException
    {
        return c.ask( message.toXMLElement( ) );
    }

    /**
     * Sends the specified message to the server and returns the reply.
     *
     * @param element The element (root element in a DOM-parsed XML tree)
     *       that holds all the information
     * @return The answer from the server or <code>null</code> if either
     *       an error occured or the server did not send a reply.
     * @see #sendAndWait
     * @see #send
     * @exception IOException
     */
    public Element ask( Element element ) throws IOException
    {
        return c.ask( element );
    }

    /**
     * Handle a reply element using the client input handler.
     *
     * @param reply The reply <code>Element</code> to handle.
     * @return The reply <code>Element</code>.
     */
    public Element handleReply( Element reply )
    {
        if ( reply != null )
        {
            try
            {
                return c.getMessageHandler( ).handle( c, reply );
            }
            catch ( FreeColException e )
            {
                logger.log( Level.WARNING, "Could not handle reply: " + reply,
                            e );
            }
        }
        return null;
    }
}
